Generally speaking about 40% - 50%. My muzzle braked .308 kicks like a .223 or less when I use 110gr bullets. Bullet weight is a big part of the recoil equation. 168gr bullet generates about 30% more recoil than a 110gr in .308, so try shooting a lighter bullet for target shooting. Honestly, I have never heard anyone describe a .243 as a hard kicker, and I thought the same about my 11 lb .308 until I started putting 30+ 175gr bullets downrange in an hour.

http://www.handloads.com/calc/recoil.asp